A stone is tied to one end of a light inextensible string of lengthl and made to rotate on a vertical circle keeping other end of the string at the centre. If speed of stone at the highest point is v (v > (gl)1/2) then its speed at the lowest point is:-

a) (4gl)1/2
b) (v2+2gl)1/2
c) (v2+gl)1/2
d) (v2 + 4gl)1/2
Kindly answer sir/mam.

KE at lowest point=KE+PE at highest point:12mv2=12mv2+mghmv'2=mv2+2mghv'2=v2+2gh    =v2+2g2L    =v2+4gL v'=v2+4gL12Ans: Option - d

  • 76
  • -27
What are you looking for?